The present invention relates to an optical disk device, and in particular, to a method of focus jump in a seek process to move to a desired address in recording and reproducing operations for an optical disk including a plurality of information recording layers.
For Digital Versatile Disks (DVD) and Blu-ray Disks, there are prescribed two-layer disks including two information recording layers. However, a need exists for disks of larger capacity. For such higher-capacity disks, research and development are underway to increase the number of recording layers per disk.
JP-A-2003-16660 describes a focus jump process in which before conducting the focus jump, a spherical aberration correcting element is moved under a condition such that focus servo control is within a predetermined control range and is suitably performed for a target layer.